Resource World Magazine

66 www.resourceworld.com f e b r u a r y / m a r c h 2 0 1 6 aLTErNaTIVE ENErGy rEVIEw Developments in Alternative energy by Jane Bratun hybrId-electrIc ProPulsIon In shIPs PowerIng a greener future A new generation of hybrid-electric marine vessels may soon be coming to a port near you. Introduced in Europe, fuel- saving hybrid-powered boats are gaining acceptance in North America. Founded in 2009, corvus energy, with head offices in Richmond, British Columbia and a newly opened European office in Bergen, Norway, provides custom-tailored, high- power, energy storage, systems (ESS) for hybrid and electric propulsion in marine, oil and gas, and port applications. The majority of hybridized vessels (more than 90% of large commercial hybrid vessels in the world) use a Corvus ESS, including the MF Ampere, the world's first all-electric car ferry; Teso Texelstroom, the world's greenest passenger ferry as well as the Selfa–Elmax, the world's first all-electric commercial fishing boat. Corvus ESS's are built rugged for the harsh marine environment and are designed as solid state units and are resistant to water, vibration, impact and electromagnetic interference. They require minimal maintenance after commissioning and are designed to provide years of reli- able service. System performance may be monitored from any location in the world using the Corvus Gateway monitoring sys- tem. The state of health, state of charge, and many other parameters may be moni- tored remotely, and the Corvus Gateway also allows for remote software upgrades as required. Corvus' cell balancing is integrated as a standard and eliminates complex and potentially unsafe cell-to-cell power trans- fer risk such as a fire or failure. The Corvus Energy Battery Management System (BMS) is a proprietary system that works auto- matically to equalize all cells in a pack. With this system, the battery is kept safe while optimizing usable capacity. Cell bal- ancing is active in that it reduces the state of charge of the high cells and leaves the low cells alone. This cell balancing pro- vides battery system peak performance and maximizes system lifespan. The unique BMS manages voltage, current, and temperature and keeps the battery in a safe working mode at all times. External communications with vessel system com- ponents create an inherently overall safe system. Corvus Energy lithium-ion polymer batteries are based on a patented nickel- manganese- cobalt (NMC) chemistry. NMC polymer provides approximately 25% more energy and power density com- pared to lithium iron phosphate (LiFePO) formulas. When combined with the ultra- low internal resistance of the cell, the batteries provide a much higher usable power source that may be used to replace diesel-scale power in many industrial applications. Multiple battery modules can be connected in series to create a high voltage pack. The ESS is based upon a 50V or 100V standard module (50V at 150Ah, 100V at 75Ah). These modules may be connected in series up to 1050V as required by the customer. Standard capacity is rated at 6.5 kW-hr nominal. According to Corvus, NMC polymer is one of the safest lithium chemistries available and, when combined with software and mechanical fail safes, provides an unparalleled level of safety. In the event of a failure beyond the scope of the Corvus ESS, the system enters a controlled shutdown mode. If further mitigation is required, the Corvus ESS can communicate with fire suppression sys- tems. The component mechanical design limits propagation in the unlikely event of a thermal runaway (TR). Independent test- ing laboratories have proven the Corvus design limits TR to one module, and the design is also immune to TR induction by external fire, such a as fire in a nearby die- sel generator. Corvus boasts the only lithium bat- tery type approved by the maritime rules and standards group, DNV-GL, which provides classification and technical assur- ance, as well as certification services to the maritime, oil and gas and energy indus- tries, Lloyd's Register, a global provider of marine classification services, and the American Bureau of Shipping, which sets standards for safety and excellence in ship classification. On another front, confidential data from maritime industry insiders based on engine size and the quality of fuel typi- cally used by ships and cars shows that 15 of the world's biggest ships may now emit as much pollution as all the world's 760 million cars. Low-grade ship bunker fuel (or fuel oil) has up to 2,000 times the sulphur content of diesel fuel used in US and European automobiles. The UN's International Maritime Organization and the EU have tightened

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